Car hire is the part of a trip where the price you agree and the price you pay diverge most often. Rentalcars.com — the car arm of Booking Holdings — is the largest broker in the business, and understanding what a broker is explains both why its prices are low and why its reviews are mixed.
What a broker actually does
You book with Rentalcars.com. You collect the car from Avis, Sixt, Europcar, or a local operator with three branches and a yard near the airport. Rentalcars.com does not own a single vehicle.
That structure produces the advantage: by aggregating demand across suppliers, the broker negotiates rates below what those suppliers publish themselves, and it can show you a local operator at half the price of the international brand next to it.
It also produces the problem: you have a contract with the broker for the booking and a separate contract with the rental company for the car. When something goes wrong, those are two conversations.
The insurance question, properly explained
This is where most people lose money and it is worth being precise.
Almost every rental comes with a large insurance excess — often €1,000–2,500. The rental company will offer to reduce it at the counter for a daily fee that is usually eye-watering.
Rentalcars.com sells its own cover, typically branded as full protection, at a much lower daily rate. It is not the same product. The broker's cover is a reimbursement policy: the rental company still holds your deposit, still charges you for damage, and you then claim the money back from the broker's insurer with the paperwork.
That is a genuine saving if you understand it. It becomes a problem if you arrive expecting the counter to recognise your cover — they will not, because it is not theirs — and if you are not prepared to have a four-figure hold placed on your card.
The practical checklist:
Bring a credit card in the main driver's name with enough limit for the deposit.
Photograph the car in detail, all sides, wheels and interior, before leaving the bay.
Photograph the fuel gauge and mileage at collection and return.
Get the return checked and signed if anyone is available.
Keep every document. A reimbursement claim is a paperwork exercise.
The counter experience
A low broker rate means a low-margin rental for the supplier, and the supplier will try to recover it at the desk. Expect to be offered the upgrade, the excess waiver, the prepaid fuel and the additional driver, sometimes persistently and occasionally with the suggestion that your existing cover is inadequate.
It is not inadequate; it is different. Decline politely and expect the process to take longer than it should.
Supplier variance
The other risk the broker model introduces is that "cheapest" often means a small local operator with an off-airport lot, a shuttle bus, and a queue. Sometimes that is fine. Sometimes it means an hour of your holiday and a car with a scratch nobody wants to discuss.
Rentalcars.com does show supplier ratings, and they are worth more attention than the price. A supplier below about 7/10 with a lot of reviews is telling you something, and the £30 you save is not worth the morning.
When to book direct
If the rental company's own price is within roughly 10–15% of the broker rate, book direct. One contract, one company, your loyalty number recognised, and a counter that acknowledges the cover you bought from them. That simplicity is worth a modest premium.
Fuel policies, ranked
The fuel policy is the second-largest source of unexpected cost in car hire after damage, and the differences are not subtle.
Full-to-full is the only good one. You collect full, return full, pay for what you used at pump prices. Always prefer it, even at a slightly higher headline rate.
Full-to-empty (sometimes called pre-purchase) means you buy a tank at the supplier's price — typically well above the pump — and return it as empty as you dare. You are paying for fuel you will not use, and the supplier's rate includes a service charge.
Same-to-same with a partial tank is workable but requires you to return it at exactly the level shown, which is difficult to judge and easy to be charged for.
Rentalcars.com displays the policy on the results page, which is to its credit. Filtering for full-to-full and accepting a slightly higher rate is usually cheaper in total than the alternative, and it removes an argument at the return desk.
The airport surcharge question
Off-airport suppliers are cheaper because airport locations pay a concession fee that is passed to you, often 10–20% of the rental.
The saving is real. So is the cost: a shuttle bus that runs every twenty minutes, a lot you cannot find on return, and an extra forty minutes at each end. On a two-week rental that trade is clearly worth it. On a two-day rental with an early flight home, it is not.
Read the pickup instructions before booking, not after. "Shuttle service" and "meet and greet" mean different things and both mean "not in the terminal".
Verdict
6.0. Rentalcars.com does what it claims — it finds cheaper car hire than you will find alone, across more suppliers than anyone else lists. The savings are real and the comparison tools for fuel policy and mileage are better than most.
It sits at the bottom of the "works, but something material counts against it" band because the broker structure pushes complexity onto the traveller at exactly the moment they are least able to deal with it: tired, at a counter, being told their insurance is not valid here. Know what you have bought before you land.
